This invention relates to a wear cap style excavating tooth and, more particularly, to a tooth assembly wherein the adapter is equipped with special lock means to prevent wear cap loss.
A successful wear cap style excavating tooth is seen in co-owned U.S. Pat. No. 4,326,348. There, the adapter is equipped with top and/or bottom wear caps which are normally held in place by the point, viz., the earth-engaging element of the assembly. However, from time to time, points break or otherwise become dislodged from their mounting on the adapter--in which case there is nothing present in the assembly to prevent loss of one or both of the wear caps, depending upon whether one or two are used.
A simple solution would be to weld the wear caps in place but this defeats the goal of workers in the excavating art which is to have the wearable elements readily replaced. Over the years, many designs have been advanced to retain the point in place under shock loadings but still render the point easily removable when replacement is indicated. Depending upon the digging conditions, from 5 to 20 points normally are installed during the life of the adapter.
Although the wear cap does not take quite the punishment of a point, it is still subjected to serious abrasion as well as shock loads and the goal of having a replaceable wear cap--several during the life of an adapter--would be frustrated by welding.
On the other hand the integrity of the adapter must be maintained because it is the principal element for transmitting loads from the point to the excavator, viz., bucket, dipper, dredge, etc. So, removal of material from the adapter to provide a typical pin lock is not desirable.
The invention has overcome these interrelated problems by providing a lock means in one or both of the side walls of the adapter which normally is unstressed except when the principal restraint against loss of the wear cap is removed as by breakage of a point.
More particularly, the adapter side wall in a position generally intermediate the length of the wear cap is equipped with a cavity into which a lock is resiliently, removably mounted. The wear cap is equipped with a notch means in alignment with the cavity, and hence the lock means, to achieve the objective of the invention.
Other objects and advantages of the invention may be seen in the details of the ensuing specification.